Existing keyboards or keypads for small handheld devices often use the standard 12-key telephone keypads (herein collectively referred to as keypads). These keypads typically have four rows of three buttons. The first three rows are typically formed from the numbers 1-9, arranged left to right, top to bottom, in increasing order. The fourth row is formed from the keys ‘*’ ‘0’ and ‘#’. Alphabetic values are ascribed to keys 2-9 in a standardized alphabetic order. Typing text using such keypads requires the user to input data in an unfamiliar manner. Other kinds of keyboards follow the Dvorak or, more commonly, the QWERTY keyboard models and are used in portable handheld devices such as the RIM 950 Wireless Handheld™. This kind of keyboard, when adapted to handheld devices, uses a plurality of small individual keys optimised for operation with the thumbs of the user. However, such a keyboard has considerably more keys than a keypad and the larger number of individual keys requires more space on a printed circuit board (PCB) than a keypad. Typically, each key requires its own footprint and switch on the PCB. Because of the relatively small size of such handheld devices, PCB space is limited and a QWERTY or Dvorak type keyboard takes up valuable real estate on the PCB.
Such a keyboard also requires a great deal of tooling in order to accommodate the large number of individual keys in the housing of a handheld device. This tooling adds to manufacturing costs. Furthermore, on a device with a QWERTY style keyboard, it is difficult to enter numerical inputs such as a telephone number. Traditionally phone numbers are entered using keypads, and having to use a QWERTY style keyboard for such inputs, where the numbers appear in a row above the letters, is considered awkward by users.
It is, therefore, desirable to reduce the number of keys necessary for a QWERTY or DVORAK type keyboard layout used with handheld devices. It is, also desirable to combine the functionality of a QWERTY style keyboard and a keypad for use in a dual-mode communication device.